Hoya Assigned Patent

Hoya Corporation, Tokyo, Japan, has been assigned a patent (11545178) developed by Osakabe; Kinobu, Tokorozawa, Japan, for “substrate for magnetic disk and magnetic disk.”

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A non magnetic substrate for a magnetic disk includes a substrate main body having two opposing main surfaces and being a glass substrate main body or an aluminum alloy substrate main body, and a metal film made of an Ni—P alloy and provided on the main surfaces and an outer circumferential edge surface of the substrate main body. The non magnetic substrate has a thickness (T+D) of 0.57 mm or less, which is the sum of a thickness T of the substrate main body and a thickness D of the metal film. The non magnetic substrate has a diameter of 90 mm or more. A ratio D/T is 0.025 or more. The outer circumferential edge surface of the substrate main body forming an interface with the metal film has a surface roughness maximum height Rz of 0.5 μm or more.”

The patent application was filed on 2021-05-07 (17/315145).